Do a conformational search
producing multiple results.
SCONFANAL*
Do a conformational search
producing only a single, lowest energy, result.
SLCONFANAL*
Menu command to generate
a library of conformers. Similar to combining the following
keywords: SCONFANAL SEARCHMETHOD=SYSTEMATIC
REPRUNECONFS=11,15,0.75
SEARCHMETHOD=
SYSTEMATIC to force the systematic
algorithm.
MONTECARLO or MC to force the
Monte Carlo algorithm.
THOROUGH to
increase the default bond-rotation by a factor of
three, and also
set the KEEPALL
keyword.
SPARSE Use the Systematic-sparse method
searching for 2000 randomly selected conformers. See
the SPARSE= keyword for
more information.
REREAD Re-read a previous run which has deposited
result in the proparc file with the
SAVEINPROPARC option. This is useful in trying
different pruning options (see PRUNEMETHOD) on a
KEEPALL run.
Set the maximum number of returned
conformers to N. The program attempts to select the
most diverse set representing the entire population
within the energy
Sets the maximum (delta)
energy at which a trial conformer will be saved in the
data set.
Conformers with an energy greater than the current minimum energy
plus this value are rejected.
10.0 (kcal/mol)
KEEPALL
Keep all generated conformations.
This is similar to maximizing MAXCONFS and
WINDOW options, but will also keep some
conformers typically thrown away because of bond strain.
MAXITER= CONFSEXAMINED=*
Maximum number of attempted molecules.
Only meaningful for the MONTECARLO method.
This is controlled from the "Maximum Conformers Controlled"
entry in the setup panel.
Changes the default 6-member ring move (cyclohexane) to
attempt to find the twist-boat conformation. This
dramatically slows down the algorithm as the number of
possible moves changes from 2 to 27. If
FINDBOATS is used the WINDOW= value is increased
to 15 kcal/mol as twist-boat conformations are
typically higher in energy (~6 kcal/mol for
cyclohexane).
off
SKIPBOATS
Uses the fast cyclohexane move of correlated flips.
on
STARTTEMPERATURE=
The initial temperature for the
monte carlo/simulated-annealing algorithm.
5000 K
NORIGID
Do not attempt to do any
'rigid moves' but rely on constraints to get the
correct structure. This will likely slow down the
algorithm.
NOOPT
Do only rigid moves and single
points. Do not attempt to re-minimize. (Only useful for
small "dynamic constraint" systems).
IGNORENOES
Ignore any NOE constraints in the system. The default is to
use the NOE constraints as a filter only.
CONSTRAINNOES
Pass any NOE constraints on to the optimization
engine. (Currently only supported by mechanics.) Thus all
intermediate results satisfy the NOE constraints. The
default is to use the NOE constraints as a filter.
This can lead to some highly strained conformations and is
not advised for most conformational searching, but can be
usefull in some geometry optimization cases.
NOEBIASE=
Used to bias the energy to favor conformations that
satisfy the NOE constraints. By default this is
turned off. Must be a positive number.
0.0 (kcal/mol)
SAVEINPROPARC
Instead of generating a new list of conformers
save the conformers in the property archive for use in
Spartan's database applications or the
"Similarity Library/Analysis" modules.
PRUNEMETHOD=i
Select a different algorithm when deciding which of the
conformers to be saved.
Default method of pruning out higher energy
conformers, and attempting to keep a diverse set of
the low energy conformers using the RMS-torsion
definition of nearness.
Use a binning algorithm using the moments of
inertia [(3*Ismall/Itot)^2], polar surface area,
dipole, and internal dihedrals as measures of diversity.
2 .. 9 are small variants on the binning algorithm
(not tested yet).
Use a cluster algorithm, which is controlled by the
DISTANCEMEASURE keyword.
Modified version of 10 but attempt
to keep the central molecule in a cluster, as opposed
to the 'lowest' energy in a cluster.
(The default is 0.)
REPRUNECONFS REPRUNECONFS=i,j,tol
Rerun the pruning algorithm as a property calculation.
the optional i. i. tol are values for
the
PRUNEMETHOD=i, DISTANCEMEASURE=j, and
DISTANCEISNEAR=tol keywords, respectively. This
keyword is a 'property' keyword, and can only be used
after a main conformation run which has been executed with
the SAVEINPROPARC keyword.
A scalar number used to measure distance between conformers.
Using differences in the torsion values of important
dihedrals. (The default.)
Use the RMS xyz distance of the heavy atoms of a
molecule moved to minimize this RMS value.
Use the RMS xyz distance of the heavy atoms of a
molecule aligned to the maximally aligned structure.
Use the score of the maximally aligned structure.
Use the number of atoms not aligned in the maximally
aligned structure. Then add (1-normalized-score) to
discriminate among conformers with same number of
'aligned' atoms.
Use the number of atoms not aligned in the RMS-xyz
distance aligned structure
11,12,13,14,15,16 Use a pharmacophore
structure for alignment, as opposed to the atomic
structure used in 1,2,3,4,5,6.
The "maximally aligned structure" and it's score is
discussed in the align FAQ.
PRUNETOLERANCE=x
In the cluster pruning algorithms conformers are
considered "near" if they are within this value. If this
value is set to zero, this tolerance is not used, and the
nearest pairs will be pruned until the number of
conformers desired is reached. See
DISTANCEMEASURE
for the units and
definition of distance used in these algorithms.
A modification of the systematic search, where a
(random) subset of the systematic conformers are tried.
If X > 1 then a total of X (random)
conformers will be attempted. If X < 1
then a fraction (x) of the total conformers will be
attempted.
CONF_SELECTION_RULE=i*
There are a number of default
rules used to determine
which bonds to rotate.
These rules are split into different classes, each of
which is useful for different types of problems.
Rules used for all rule sets are:
Do not rotate bonds around ligand points (such as
the Cp ligand)
Do not rotate around double bonds.
Do not rotate amide bonds
Do not rotate around symmetric bonds such as -CH3
and benzene rotors
There are currently 5 sets of rules:
Legacy Spartan 02 rule set.
Do not rotate amide bonds
Legacy Trident rule set used in the pharmacophore
searching algorithm
Do not rotate ester bonds
Do not rotate around terminal xH bonds, such as
-OH or -NH2.
Normal.
Do Not rotate ester bond
Rotate amide bond
Do not attempt to find twist boat conformations.
Attempt to recognize when different conformation
of chair like rings (cyclohexane) can be
reproduced by a single rotation.
Recognize affects of fused rings
Skeletal is an extension of the 'Normal' mode
but designed to be quicker by only finding 'important'
minima.
Do not rotate around terminal xH bonds, such as
-OH or -NH2.
All bonds to nitrogen are given a fold of 2,
even if they formally have a 3-fold rotation.
Do not rotate carboxylic acid groups.
Do not rotate methoxy groups and ethane groups
when attached to benzene.
Do not search for multiple conformations of piperazine.
Do not rotate long alkyl chains.
Exhaustive is an extension of 'Normal' mode,
but designed to find even high energy minima.
Rotate ester bonds
Attempt to find boat conformations of
cyclohexane like rings.
Attempt to find conformations of constrained 5
and 6 member rings.
Normal12 Deprecated. The default value in
iSpartan (our iPad/tablet product).
Thorough is an extension of 'Normal' mode,
but designed to find even high energy minima.
Flips some non-planar nitrogens
In Spartan 18 we've added a series of rules and algorithms
to better deal with rings with more than 6 flexible bonds.
These new methods are noted by adding the "(rings)" postfix
in the Preferences/Settings Panel for the keyword by adding
10 to the rule integer (i.e. 13 is Skeletal with rings).
Spartan ships with the default of "12"
set in the preference panel.
If you were to use this as a keyword you could either use
CONF_SELECTION_RULE=12 or
CONF_SELECTION_RULE=NORMAL+RINGS.
This value can be set as a keyword, or as a system wide
preference in Spartan's
preference dialogue (Options Menu).
It is important to remember that the selection rules are
overridden when users specify atoms/bonds from the
'Set Torsions' mode. Thus this keywords should seldom
be used and instead use the default and examine each molecule
via the (Menu -> Geometry) "Set Torsions" mode.
If you are using this keyword it should likely be combined with
the IGNORE_USERSELECTION
keyword.
IGNORE_USERSELECTION
Ignore the bond selection
from the user
(via the Menu -> Geometry"Set Torsions" mode).
Instead use the default rules for determining rotatable bonds.
(User defaults are set whenever the user enters the 'set
torsions' mode.)
DRYRUN
Execute only the setup part of conformational analysis.
This is only used in debugging.
DISTANCEMEASURE=i
Measure to use in determining distance between two conformers.
TRACK_DOUBLE=NO
Double bonds to rotate
(greater than 90 degrees) even if not selected as flexible rotors.
YES
TRACK_CHIRAL=NO
Allow atoms to change chirality.
YES
CONFSEED=
The starting point for the
random number generator.
CONSTRAIN*
PARTIAL*
NOSYMTRY*
keywords passed to underlying method
FREQ*
Will do a frequency calculation
on the final candidates.
ANHARMONIC
An extra second-order vibrational perturbation theory (VPT2w)
and a Transition-optimized shifted Hermint (TOSH) calculation will be done
to get c
ANHAR=TRUE
allow anharmonic calculation.
(Job must be a single-point energy only calculation
with the frequency property checked). Combine with the
VCI= keyowrd to run a VCI calculation.
VCI=n
The number of quanta involved in a
Vibration Configuration Interaction (VCI) calculation.
0
(max=10)
MODE_COUPLING=n
The number of modes coupling in the third and fourth derivatives calculations.
2
(max=4)
IGNORE_LOW_FREQ=300
Low frequencies that should be
ignored during anharmonic correction calculation. (i.e. assumed rotational)
300 cm-1
VIBMAN_PRINT=n
n can be 1 .. 6 and increase the amount of vibrational (and anharmonic information)
printed in the verbose output. Use with the KEEPVERBOSE in order that this information
is not deleted.
PRINTLEV=
Control Printing. See
Description of the output file for
more information. PRINTLEV=2 displays a label for each conformation. PRINTLEV=3 dumps the intermediate minimization output to the
main output window
...other keywords...
Keywords unrecognized by the conformation and energy
profile module will be passed to the
underlying method. See below for
some commonly used keywords.
Keywords specific to the energy profiles
DYNCON* DYNCON2
Do dynamic
constraints/Energy Profile.
SDYNCON
Do a energy profile but only return one result.
(Usually, this result is a transition state, but if no
local maxima exist the local minima will be returned.)
This is not a
recommended option, and is used primarily for debugging
purposes.
DYNCONMETHOD=
If there are multiple
constraints how are these constraints applied
SEQUENTIALly. First one then the next.
On a grid GRID, such as a phi-psi
plot. or
TOGETHER, where both constraints are
adjusted in concert with each other.
TOGETHER
KEEPSYMMETRY
Attempt to maintain the
starting molecule's symmetry.
NORIGID
Do not attempt
'rigid moves' but rely on constraints to get the
correct structure.
NOOPT
Do only rigid moves and single points. Do not
attempt to re-minimize.
NOMECHPREOPT
Do not prefix each minimization with a mechanics constrained
optimization. This is only meaningful for non-mechanic's methods
such as AM1.
RIGIDONLY
Do only
rigid moves and single points. Do not
attempt to re-minimize. (Only useful for
small "dynamic constraint" systems).
SAVEFILES SAVEFILES=2
Save temporary files. Useful for debugging.
SAVEFILES=2 (or greater) will save even more
intermediate files including those of the sub-jobs.
SAVETEMP=
Not-implemented
NAMEPREF=abc
Save conformers (or energy
profile steps) using the name 'abc'. (This will force the
creation of a new file even if executing a 'Equilibrium
Conformer' job.
REPLACE
Not-implemented
* Keywords marked with an asterisk '*'
should not be typed in. They are generated by the setup
panel.
Other useful keywords for the energy profile module
Keywords not recognized in the conformer/energy-profile module will be
passed on the underlying method. Following are some keywords found to
be useful.
POSTSOLVENT=...
(mechanics only)
Add the solvent model as a final
perturbation. Thus, all minimizations are done with the
base force field and a solvation 'correction' is applied
to the final energy. SM50R is the most used
mechanics solvation model. (POSTSOLVENT=SM50R)
Geometry Optimization Keywords
GEOMETRYCYCLES=* OPTCYCLES=*
How many geometry steps to try before failing.
If you are having difficulty converging this can be increased. However
if the job is continually running out of cycles it may be an indication
that either the starting geometry was far from a good starting point, or that
something unexpected (like forming a new bond and/or breaking a bond is occurring.
(OPTCYCLES= is a deprecated pseudonym for this keyword.)
GRADIENTTOLERANCE=* TOLG=*
The maximum gradient on any atom must be less than this amount.
=.0007
DISTANCETOLERANCE=* TOLD=*
The maximum predicted relative atomic movement must be less than this amount (in bohrs).
=.00002
ENERGYTOLERANCE=* TOLE=*
The energy difference from the previous step must be less than this amount
(in hartrees)
=.000001
GEOMTOL=*
A short cut for various geometry tolerance settings:
label
GradientTolerance
DistanceTolerance
EnergyTolerance
=DEF16
0.000300
.0012
.0000010
=TIGHT
0.000095
.0008
.0000010
=DEF
0.000700
.0014
.0000200
=LOOSE
0.000800
.0015
.0000762
=PRELIM
0.000800
.0019
.0002285
The geometry is considered 'converged' when two of the three conditions are met.
Typically the gradient condition is the most sensitive.
NOGEOMSYMMETRY
This turns off the use of symmetry in the optimizer.
This includes "local-atomic" symmetry used in the geometry optimizer which recognizes
that sp3 carbons are roughly tetrahedral, and sp2 carbons are roughly planar. This can
slow down the optimization by a factor of two, but in difficult cases such as highly
coordinated atoms or large geometry changes this can help convergence.
HESS=UNIT
Instead of using the default hessian, use a simple 'unit-diagonal' hessian.
If you don't trust the current/previous hessian this is an option. It is never a great
approximation of the true hessian but it is never 'very-bad'.
Controlling the ESP (electrostatic potential) algorithm
SHELL=
The farthest extent of the shell of points to used to
fit the electrostatic potential.
5.5 bohrs
WITHIN=
A buffer between the standard vdW radii
and the nearest points in the shell of external points.
0.0 bohrs
ELCHARGE=
An integer number representing the number of points
per cubic Bohr.
1
NOELCHARGE
Skip the electrostatic charge calculation.
CHELPDENSITY=
An integer number representing the number of points
per cubic Bohr.
1
SVD=
Use the CHELP-SVD (Single value decomposition) algorithm
to calculate the charges. Setting to 0 turns off. There
are a number of variants to this algorithm:
An older, deprecated, algorithm.
Don't prune points.
Attempt to prune terms (vectors) which do not
significantly improve the accuracy.
0
SVDTHRESH=
.00001
CHELPPOINTS=
Algorithm which places points into the shell.
Use a rectangular grid.
Use a spherical grid with approximate constant density.
Use a spherical grid with density decreasing ~1/radius.
1
CHELPEXTRA=
Choose more points than just nuclei. This
allows one to approximate a multipole expansion around
each nuclei.
Use 1 point per nuclei.
Use 7 points per nuclei.
Use 10 points per non-hydrogen nuclei.
Use 14 points per non-hydrogen nuclei.
Use bond orientated, atom centered dipoles
Modified version of model 4 adding extra points on
atoms with 2 bonds.
same as 5, but add dipoles to hydrogens
Dipoles on all terminal atoms
A flag to cycle through all models
By default electrostatic charges are reported using method
'0'. However, points using method '2' are
also calculated and available to be used.
0
CHELPPRINT=i
Print more information about the ESP charge calculation.
Integers greater than 1 cause successively more printing.
Also available is TERSE
1
Keywords to analyze the wave-function
PRINTMO1
Print the Molecular orbitals.
PRINTORBE ORBE
Print molecular orbital energies.
PRUNEVIRTUAL=x PRUNEVIRTUAL=NONE
Delete unoccupied molecular orbitals 'x' above the
LUMO. This is useful in decreasing the size of the
molecular data stored on the disk and in making the output
of PRINTORBE and PRINTMO more reasonable.
10
POSTHF
Use the post Hartree-Fock wave function if available. On by
default for MP2 type calculations.
NOPOSTHF
Do not use the post HF calculations. For MP2 this means, to
use the HF wave function instead of the corrected
MP2 wave function,
Do the natural bond order hybridization analysis. See the
above discussion. Possible values
for yy are:
NORMAL, the default.
IONIC to see ionic contributions.
3C to examine three-center contributions.
MULPOP1 PROP:MULPOP=3
Print the Mulliken charges. With a value of 3, the full
matrix is printed,
1
NOMULCHARGE NOMULPOP
Skip the Mulliken charge calculation.
POP1
Print the natural atomic charges.
NONATCHARGE
Skip the natural atomic charge calculation
PRINTCHG PRINTCHARGE=x
Print a summary of charges and bond order. A (much)
shortened version of what is printed with the
MULPOP, POP, BONDORDER and NBO keywords.
If x=1 only atomic charges are printed.
If x=2 Mulliken bond orders are shown.
If x=2 natural bond orders are shown.
DEORTHOG
Deorthogonalize semi-empirical MOs before calculating properties.
DIPOLE
Print out the Cartesian components of the dipole moment.
NODIPOLE
Skip the calculation of the dipole moment.
BONDORDER
Print out Mulliken and Lowdin bond order matrices, plus
atomic and free valences for open-shell
wave functions.
PRINTNBO
Print the AO to NBO transformation
NOPOP
Skip the natural bond order (NBO), and natural charge
calculation.
DOEPN
Print out the "Electronic Potential at Nuclei" for Oxygen and
Nitrogen.
DOEPN=SKIP to skip calculation. (By default the
calculation is stored in archive but not printed.
Enter DOEPN=ALL to print all atoms.
Specify that the elpot+polpot grid will be used to generate
atomic charges. This is valid for closed-shell HF-only
molecules.
PRINTOVERLAP PRINTS
Print the overlap matrix as a lower
triangle. Use in conjunction with the
PRINTMO keyword
if you want to do your own 'home-brew'
quantum mechanics calculation.
See the discussion of atomic orbitals
for more information. (The PRINTS spelling is
deprecated.)
POLAR
Calculate the static polarizability of the
molecule.
For Hartree-Fock and semi-empirical methods
this will also calculate the static hyperpolarizability.
See our discussion above for more details on
how to calculate polarizability.
HYPERPOLAR
Calculate the static polarizability and hyperpolarizability
of the molecule. Not available for DFT methods using
pure basis sets (i.e. 6-311G etc.).
POLAR=a,b,c...UNIT
HYPERPOLAR=a,b,c...nnUNIT
Calculate the polarizability at different frequencies.
There can be multiple frequencies, here represented by
'a','b', and 'c', but could be more (or fewer) comma
separated values.
UNIT should be replaced with au, nm, ev, hz
or cmInv.
For example:
POLAR=0.0,0.03,0.05,AU
Note that an energy of 'zero' (0.0) is a way of specifying
the static (infinite wavelength) case.
POLAR=WALK,start,end,step,UNIT
This format of the POLAR keyword allows one to
specify a range of frequencies/energies.
This WALK format is also available for the
HYPERPOLAR keyword. As an example:
POLAR=WALK=0,.1,0.025,AU
EMFIELD=
Can apply
an external (multipole) field to the main calculation.
Thus allowing a numerical way of calculating static polarizability.
One stipulate multiple comma separated Cartesian terms representing
dipoles (X,Y,Z), quadrapoles (XX,XY,YY etc.).
For example:
EMFIELD=X~0.1 EMFIELD=X~0.1,Y~0.05,ZZ~0.001
The units are in "atomic units". ie. 1 a.u. = 51.422 V/Å
Keywords related to frequencies and thermodynamics
NOFREQ
Do not do any frequency or thermodynamic calculation even if
there is a good Hessian. (By default, if a high quality
Hessian is available, frequencies will be calculated.
FREQSCALE=x FSCALE=x
Scale all the frequencies by a factor 'x'.
DROPVIBS=x
When calculating thermodynamics values, ignore all
modes with frequencies below 'x'.
CLAMPTHERMO CLAMPTHERMO=x
When calculating thermodynamics values, clamp enthalpy terms
at 'x'RT. (If no 'x' given 1/2 is used.)
Entropy will be clamped at2x'x'R (i.e. R by default).
For the default 'x'=1/2 these limits imply a break in the
enthalpy and entropy near ~260 cm-1.
To turn "clamping" off use CLAMPTHERMO=NO
0.5
PRINTMODE
Print thermodynamic information for each mode.
TEMPERATURE=
Change the default temperature used in the thermodynamic
calculation.
298.15 K
TEMPRANGE=start,end,step
Print thermodynamic properties for a range of
temperatures.
PRESSURE=
Change the default pressure used in the thermodynamic
calculation.
1.0 atm
PRINTFREQ1
Print the Cartesian values of the normal mode vibrations.
This is what the 'Print Vibrational Modes' button in the
calculation dialogue.
THERMO1
Print standard thermodynamic data. This is the 'Print
Thermodynamics' button in the calculation dialogue.
PRINTIR
Print Infrared and thermodynamic information for each normal
mode vibration.
PRINVIBCOORDS
Print the coordinates of each vibrational mode.
AVGMASS ISOTOPEMASS=*
By default Spartan uses the 'most common isotope' as the
mass of atoms when doing thermodynamics calculations. (Changing
the isotope of a specific atom in the property dialogue
overrides the mass for only that atom.)
AVERAGE: Use the terrestrial average mass.
COMMON: use the most common isotope as the
atomic mass. (This is the default in Spartan.)
Isotope settings in the GUI will override this default value.
STANDARD: use the average mass, and ignore any
specific atomic mass settings set in the atom property panel.
APPROXFREQ
Calculate frequency and thermodynamic information on the
intermediate low quality Hessian. (Not recommended.)
GXTHERMO
Calculate G3 type results. (Internal keyword, should not
be used unless you know what you are doing.)
FREQ1,2
FREQ=CD2
FREQ=FD2
Calculate frequencies by numerical differentiation, using
central differences (CD) or forward differences
(FD) as opposed to analytically. Analytical methods are
usually much faster and more accurate than numerical methods
as numerical methods require 6 single point calculations
for each atom in the molecule.
Forward difference is usually %50 faster than central
differences, but is significantly less accurate and is not
recommended. The default is to use analytical frequencies if
available.
NUMERICALFREQ
Calculate frequencies by numerical differentiation, using
central differences.
Analytical methods are
usually much faster and more accurate than numerical methods
as numerical methods requires 6 single point calculations
for each atom in the molecule.
FD=xx.yy2
Step size for numerical differentiation.
0.005 bohr
DORAMAN2
Calculate the Raman intensities along with the standard IR intensities.
By default the verbose output file is deleted/pruned. (For
many jobs this can dramatically decrease the size of
.spartan files.)
Instead of using this keywords, one can set the
"Keep Verbose" check box in the
"Preferences Panel".
PROPPRINT=i PROPPRINTLEV=i
For 'i' greater than 1, print more information into the
output file. 'i' must be 4 or less.
0
PRINTCOORDS
Print the Cartesian coordinates of all atoms in the system.
ACCEPT
Accept certain error conditions and continue without a fatal
error.
BTABLE=BAD
Print out a table on all bond distances (B),
bond angles (A) and dihedral (D) angles.
If only bond distances, angles or dihedrals are required,
BAD can be replaced with B, A, or
D respectively.
NEAREST=x.y
Specify the multiplication factor (applied to
nearest-neighbor distances) when generating the geometric
information.
1.2
QSAR
Prints various QSAR descriptors. While these values are
usually calculated, and can be found in the proparc file and
in the spreadsheet this prints them to the output file.
The list of descriptors this keyword prints is:
Atomic Weight
E-LUMO and E-HOMO
Electronegativity, Hardness and Est. Polariz. (AM1 only)
Molecular Volume, Surface Area and Ovality
logP (Ghose-Crippen, Dixon, and Villar[SE only])
Exposed Surface Area
Atomic Valence
Q-minus and Q-plus (for any charges)
Free Valence
Total Overlap Population (ab initio only)
NOQSAR
Skip the calculation of QSAR descriptors.
MOMENTS
Print out the moments of inertia, in both atomic units and
inverse centimeters.
MAXVOLSIZE=i
Atomic volumes and surface areas will be calculated only for
systems with fewer than 'i' atoms.
100
SOLVRAD
In calculation of atomic areas and volumes, add this value
to the VdW radii.
VPTS=i AARCS=j APTS=k
To control the internal working of the volume calculator.
Internal keyword used for debugging and QA work at
Wavefunction. This works on the 'cell' data of the spreadsheet.
Cells with the following names are analyzed:
Reference_E=xxx.yy ; The energy in Kcal/mol.
REF_PREC_E=x.yyy ; precision (default 5.0e-8)
PROP_x=Equation ; Most spreadsheet
equations are valid
REF_PROP_x=xxx.yy ; the target value
REF_PREC_x=x.yyy ; precision (default 1.0e-4)
PARCFORMAT=i
[for internal to Wavefunction use]
If i=1 write both formats of frequency information.
If i=2 write only new format of frequency information.
i=2
Keywords related to the Intrinsic Reaction
Coordinate (IRC) calculation
Specifies the maximum number of points to
find on the reaction path. (Should be odd. The default
value of 41 yields 20 steps forward and 20 backwards.)
41
IrcStepSize=2
Specifies the maximum step size to be taken. This is in
thousandths of a Bohr. The default of 150 means 0.15 Bohr.
150
RPATH_TOL_DISPLACEMENT=2
Specifies the convergence threshold for the step. If the
atoms are moving less than this value, configuration is
assumed to be at a minima and the algorithm will stop.
The units are in millionths of a Bohr. The default value of
5000 corresponds to 0.005 Bohr.
5000
Keywords for excited state and UV/Vis calculations
ESTATE=n1,2
Choose the excited state to calculate the gradient
for. Usually this is not entered as a keyword, but is
selected by choosing 'First Excited State' in the
calculation dialogue.
1
TDA
Use the Tamm-Dancoff approximation (TDA) to the
standard Time Dependent DFT (TDDFT) algorithm.
(The TDA was the default method for DFT calculations prior to
Spartan'14v117.) This can be up to twice as fast as the default
"Full TDDFT" and produces similar, but not as precise results.
The TDA approximation also converges easier than the full
TDDFT algorithm so may be useful in cases where convergence
is difficult.
EXMULT=
For excited states we typically keep the number of electrons the same
as the ground state. This keyword can be set to
=TRIPLET, =SINGLET, or =ANY to allow more
flexibility in selecting the desired excited state.
CIS_N_ROOTS=2
To examine more orbitals in the excitation. For
systems where there are many delocalized atoms you may
want to increase this number from the default. Despite the
"CIS" in this keywords spelling, it is also appropriate for
TDDFT calculations.
>=5
CIS_TRIPLETS=FALSE2
To limit the search of excited states to only singlets.
Use this keyword only for excited state calculations. If
this is used when doing an UV/Vis spectrum calculations this
keyword will interfere with the INCLUDESINGLETS and
INCLUDETRIPLETS keywords.
=TRUE
UVSTATES=2
To examine more orbitals in the UV/Vis calculations. For
systems where there are many delocalized atoms you may
want to increase this number from the default.
Only valid when the "UV/Vis" button is selected.
>=5
INCLUDETRIPLETS2
To include triplets in the UV/Vis calculation of singlet
wave functions. The intensity of the excitation will
be small (zero) but can be useful if interested in all
lower energy excited states.
INCLUDESINGLETS2
To include singlet excitations in the UV/Vis calculation of
triplet
wave functions. The intensity of the excitation will
be small (zero) but can be useful if interested in all
lower energy excited states.
CORE=FROZEN2 CORE=THAWED
By default core electrons are not used
in post-Hartree-Fock calcultions. Use CORE=THAWED
to allow all core electrons to be excited.
N_FROZEN_VIRTUAL=n2
Reduces the number of virtual molecular orbitals used in the
calculation. Changing this number from the default, may
speed up the calculation, but may also cause inaccuracies in
the calculation.
MAX_CIS_CYCLES=n2
To change the number of SCF cycles to try before
'giving up'
on the CIS calculation. Increase if you are having
convergence problems, but waiting longer might work.
10
CIS_CONVERGENCE=x2
Decrease this number if you want quicker convergence at
the cost of precision. (Reducing to a number below
5 can give unphysical results.)
6
CIS_AMPL_PRINT=x
To print filled/unfilled molecular orbital pairs which
have coefficients larger than x. This value is in
hundredths so the default value of 15 implies an
amplitude of 0.15.
(This will go in the verbose output file, so make
sure to use the KEEPVERBOSE keyword.)
15
SET_ITER
Controls a convergence limit when converging on the excited states.
May be useful if you get the "MaxIt Reached in CIS/RPA iterations" error
message. Can also be useful in some IR (frequency) calculations.
31
Keywords related to the NMR calculations
D_SCF_MAX_2=n
The maximum number of SCF-NMR steps to try before giving up.
Typically, increasing this will allow difficult systems to converge.
75
D_SCF_CONV_2=n
The tolerance/precision used in the inner (2nd) part of the
convergence algorithm. "n" is the decimal so the
default of 2 implies 10-2=0.01.
2
D_SCF_MAX_1=n
Maximum number of tries in the inner NMR convergence
step.
40
D_SCF_CONV_1=n
The tolerance of the inner NMR convergence step.
0
Keywords specific to the coupling constant calculator
(For these keywords to work they must be appended to the
JISSC= keyword, comma separated.)
JISSC=
This keyword is controlled by the "Coupling Constants"
pull-down menu. By default we use some simple "Karplus-like"
equations for H-H coupling, but also can be calculated form
first principles
using either the Fermi-Contact approximation or the full
ncalculation.
<karplus>
MOPROP_CONV_1ST~n
Sets the convergence criterion for second-order TDSCF.
"n" is the decimal so the
default of 2 implies 10-2=0.01.
6
MOPROP_CONV_2ND~n
Sets the convergence criterion for second-order TDSCF.
"n" is the decimal so the
default of 2 implies 10-2=0.01.
6
MOPROP_MAXITER_1ST~n
The maximum number of iterations for CPSCF and first-order TDSCF.
50
MOPROP_MAXITER_2ND~n
The maximum number of iterations for second-order TDSCF.
50
Modifying DFT paramters
BIGGRID=
There are a number of keywords
related changing the grid size used in DFT calculations.
SG-1 and SG-0, small grids tuned for the
6-31G* basis sets.
SMALLGRID (Spartan's default for "simple" functionals;
SG-0 for H,C,N, and O and SG-1 for all other atoms)
EMLGRID (50,194)
BIGGRID (70,302)
VERYBIGGRID (100,434)
FINEGRID (99,590)
HUGEGRID (250,947)
In the above notation the first number is the number of
shells in the radial direction, the second number (i.e. 194,
434 etc.) is the number of Lebedev radial points.
One can also use the BIGGIRD keyword with an equal sign, to
enter a Q-Chem like grid notation. Specifically a 12 digit
number with the first six (counting leading/implied zeros)
defining the number of shells in the
radial direction and the next 6
defining the number of Lebedev radial points.
i.e., BIGGRID and BIGGRID=70000302 both refer to
(70,302)
If you want to use Gauss-Legendre angular points (a=2N^2)
instead of Lebedev numbers use BIGGRID=-rrraaaaaa
(i.e. use a negative number).
Submission Logic
RERUN RERUN=ORIGINALCOORDS
Force a rerun of the calculation throwing away
the current archive but keeping the current coordinates.
With the =ORIGINALCOORDS argument will use the coordinates prior to an
optimization if availble.
CPUCNT=n
Attempt to use n threads/cores. This will override the
thread count assigned by the queueing logic setup by your system administrator.
WARNING: This can be abused and in affect "steal" system resources from other
jobs/users using the same system so should be used with caution.
The "start from geometry", "IR", "UV/Vis and "NMR"
check-boxes in the setup panel can be overriden with these keywords. This is useful if these
steps require more keywords. Note that the options to these keywords are comma seperated
and any required equal (=) signs must be replace with a tilde (~). Upon hitting the "Enter"
key these keywords will "dissapear" and the options will be displayed in the appropriate pull-down
menu of the setup panel.
...
Notes:
1 Indicates that these
should not be
typed in as there is a button in the calculation dialogue
for it. 2 The keyword is used by a
module other than the
property module, but is mentioned here for completeness.
set in the preference panel.
If you were to use this as a keyword you could either use
CONF_SELECTION_RULE=12 or
CONF_SELECTION_RULE=NORMAL+RINGS.